It's not an opinion that many motivations for marriage are treated as illegitimate in circumstances like this, and it's not an opinion that marriage is expected to almost always involve sex.
That USCIS requires people to submit evidence that their marriage is "genuine", and can reject an application based on such evidence being insufficient, is a fact:
"The burden is on the applicant to establish that he or she is in a valid marriage with his or her U.S. citizen spouse for the required period of time. A spouse of a U.S. citizen must submit with the naturalization application an official civil record to establish that the marriage is legal and valid. If an official civil record cannot be produced, secondary evidence may be accepted on a case-by-case basis. An officer has the right to request an original record if there is doubt as to the authenticity of the record."
